Dispersion-Engineered Deep Sub-Wavelength Plasmonic Metasurfaces for Broadband Seira Applications

Journal Article · Thu Jul 20 00:00:00 EDT 2023 · Advanced Optical Materials

DOI:https://doi.org/10.1002/adom.202300979· OSTI ID:2007211

Dixon, Katelyn ^[1]; Zhu, Xiangchao ^[2]; Chen, Liang ^[2]; Montazeri, Arthur ^[2]; Matsuura, Naomi ^[3]; Kherani, Nazir P. ^[3]; Holman, Hoi‐Ying N. ^[2]

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1. University of Toronto, ON (Canada); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
2. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
3. University of Toronto, ON (Canada)

Surface enhanced infrared absorption (SEIRA) spectroscopy is a powerful tool in which plasmonically enhanced electromagnetic fields provide high-sensitivity molecular detection. Most SEIRA platforms operate at a single resonant frequency, which must be tuned to match that of the target molecule, and commonly rely on time-consuming lithographic techniques. This study presents a high-throughput and cost-effective plasmonic metasurface for broadband, tunable, and strong infrared signal enhancement. The platform is built upon the principle of dispersion-engineered plasmonic Fabry–Pérot (FP) nanocavity arrays. It offers 1) tight squeezing of infrared (IR) photons into deep sub-wavelength nano-volumes and 2) spectrally tunable near-field enhancements of up to ≈10⁶, two to three orders of magnitude higher than most optical metasurface systems. By coupling multilayer nano-thin film deposition and nanoskiving fabrication techniques, the dispersive FP metasurfaces can be rapidly and reproducibly constructed in a scalable and lithography-free manner. Using IR spectroscopy, the selective and sensitive label-free detection of a molecular monolayer is achieved at a range of frequencies. An enhancement factor of nearly 10⁵ is measured at the carbonyl (C = O) vibrational marker band of the molecule. The confluence of high field enhancement, broadband plasmonic response, and facile fabrication makes this metasurface a promising platform for SEIRA spectroscopy.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 2007211
• Journal Information: Advanced Optical Materials, Journal Name: Advanced Optical Materials Journal Issue: 1 Vol. 12; ISSN 2195-1071
• Publisher: Wiley
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SEIRA
infrared absorption spectroscopy
light localization
metamaterials
plasmonic field enhancement